includes/filerepo/RepoGroup.php

   1 <?php
   2 /**
   3  * Prioritized list of file repositories.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup FileRepo
  22  */
  23
  24 /**
  25  * Prioritized list of file repositories
  26  *
  27  * @ingroup FileRepo
  28  */
  29 class RepoGroup {
  30         /**
  31          * @var LocalRepo
  32          */
  33         var $localRepo;
  34
  35         var $foreignRepos, $reposInitialised = false;
  36         var $localInfo, $foreignInfo;
  37         var $cache;
  38
  39         /**
  40          * @var RepoGroup
  41          */
  42         protected static $instance;
  43         const MAX_CACHE_SIZE = 500;
  44
  45         /**
  46          * Get a RepoGroup instance. At present only one instance of RepoGroup is
  47          * needed in a MediaWiki invocation, this may change in the future.
  48          * @return RepoGroup
  49          */
  50         static function singleton() {
  51                 if ( self::$instance ) {
  52                         return self::$instance;
  53                 }
  54                 global $wgLocalFileRepo, $wgForeignFileRepos;
  55                 self::$instance = new RepoGroup( $wgLocalFileRepo, $wgForeignFileRepos );
  56                 return self::$instance;
  57         }
  58
  59         /**
  60          * Destroy the singleton instance, so that a new one will be created next
  61          * time singleton() is called.
  62          */
  63         static function destroySingleton() {
  64                 self::$instance = null;
  65         }
  66
  67         /**
  68          * Set the singleton instance to a given object
  69          * Used by extensions which hook into the Repo chain.
  70          * It's not enough to just create a superclass ... you have
  71          * to get people to call into it even though all they know is RepoGroup::singleton()
  72          *
  73          * @param $instance RepoGroup
  74          */
  75         static function setSingleton( $instance ) {
  76                 self::$instance = $instance;
  77         }
  78
  79         /**
  80          * Construct a group of file repositories.
  81          *
  82          * @param $localInfo array Associative array for local repo's info
  83          * @param $foreignInfo Array of repository info arrays.
  84          *     Each info array is an associative array with the 'class' member
  85          *     giving the class name. The entire array is passed to the repository
  86          *     constructor as the first parameter.
  87          */
  88         function __construct( $localInfo, $foreignInfo ) {
  89                 $this->localInfo = $localInfo;
  90                 $this->foreignInfo = $foreignInfo;
  91                 $this->cache = array();
  92         }
  93
  94         /**
  95          * Search repositories for an image.
  96          * You can also use wfFindFile() to do this.
  97          *
  98          * @param $title Title|string Title object or string
  99          * @param $options array Associative array of options:
 100          *     time:           requested time for an archived image, or false for the
 101          *                     current version. An image object will be returned which was
 102          *                     created at the specified time.
 103          *
 104          *     ignoreRedirect: If true, do not follow file redirects
 105          *
 106          *     private:        If true, return restricted (deleted) files if the current
 107          *                     user is allowed to view them. Otherwise, such files will not
 108          *                     be found.
 109          *
 110          *     bypassCache:    If true, do not use the process-local cache of File objects
 111          * @return File object or false if it is not found
 112          */
 113         function findFile( $title, $options = array() ) {
 114                 if ( !is_array( $options ) ) {
 115                         // MW 1.15 compat
 116                         $options = array( 'time' => $options );
 117                 }
 118                 if ( !$this->reposInitialised ) {
 119                         $this->initialiseRepos();
 120                 }
 121                 $title = File::normalizeTitle( $title );
 122                 if ( !$title ) {
 123                         return false;
 124                 }
 125
 126                 # Check the cache
 127                 if ( empty( $options['ignoreRedirect'] )
 128                         && empty( $options['private'] )
 129                         && empty( $options['bypassCache'] ) )
 130                 {
 131                         $time = isset( $options['time'] ) ? $options['time'] : '';
 132                         $dbkey = $title->getDBkey();
 133                         if ( isset( $this->cache[$dbkey][$time] ) ) {
 134                                 wfDebug( __METHOD__.": got File:$dbkey from process cache\n" );
 135                                 # Move it to the end of the list so that we can delete the LRU entry later
 136                                 $this->pingCache( $dbkey );
 137                                 # Return the entry
 138                                 return $this->cache[$dbkey][$time];
 139                         }
 140                         $useCache = true;
 141                 } else {
 142                         $useCache = false;
 143                 }
 144
 145                 # Check the local repo
 146                 $image = $this->localRepo->findFile( $title, $options );
 147
 148                 # Check the foreign repos
 149                 if ( !$image ) {
 150                         foreach ( $this->foreignRepos as $repo ) {
 151                                 $image = $repo->findFile( $title, $options );
 152                                 if ( $image ) {
 153                                         break;
 154                                 }
 155                         }
 156                 }
 157
 158                 $image = $image ? $image : false; // type sanity
 159                 # Cache file existence or non-existence
 160                 if ( $useCache && ( !$image || $image->isCacheable() ) ) {
 161                         $this->trimCache();
 162                         $this->cache[$dbkey][$time] = $image;
 163                 }
 164
 165                 return $image;
 166         }
 167
 168         function findFiles( $inputItems ) {
 169                 if ( !$this->reposInitialised ) {
 170                         $this->initialiseRepos();
 171                 }
 172
 173                 $items = array();
 174                 foreach ( $inputItems as $item ) {
 175                         if ( !is_array( $item ) ) {
 176                                 $item = array( 'title' => $item );
 177                         }
 178                         $item['title'] = File::normalizeTitle( $item['title'] );
 179                         if ( $item['title'] ) {
 180                                 $items[$item['title']->getDBkey()] = $item;
 181                         }
 182                 }
 183
 184                 $images = $this->localRepo->findFiles( $items );
 185
 186                 foreach ( $this->foreignRepos as $repo ) {
 187                         // Remove found files from $items
 188                         foreach ( $images as $name => $image ) {
 189                                 unset( $items[$name] );
 190                         }
 191
 192                         $images = array_merge( $images, $repo->findFiles( $items ) );
 193                 }
 194                 return $images;
 195         }
 196
 197         /**
 198          * Interface for FileRepo::checkRedirect()
 199          * @return bool
 200          */
 201         function checkRedirect( Title $title ) {
 202                 if ( !$this->reposInitialised ) {
 203                         $this->initialiseRepos();
 204                 }
 205
 206                 $redir = $this->localRepo->checkRedirect( $title );
 207                 if( $redir ) {
 208                         return $redir;
 209                 }
 210                 foreach ( $this->foreignRepos as $repo ) {
 211                         $redir = $repo->checkRedirect( $title );
 212                         if ( $redir ) {
 213                                 return $redir;
 214                         }
 215                 }
 216                 return false;
 217         }
 218
 219         /**
 220          * Find an instance of the file with this key, created at the specified time
 221          * Returns false if the file does not exist.
 222          *
 223          * @param $hash String base 36 SHA-1 hash
 224          * @param $options array Option array, same as findFile()
 225          * @return File object or false if it is not found
 226          */
 227         function findFileFromKey( $hash, $options = array() ) {
 228                 if ( !$this->reposInitialised ) {
 229                         $this->initialiseRepos();
 230                 }
 231
 232                 $file = $this->localRepo->findFileFromKey( $hash, $options );
 233                 if ( !$file ) {
 234                         foreach ( $this->foreignRepos as $repo ) {
 235                                 $file = $repo->findFileFromKey( $hash, $options );
 236                                 if ( $file ) break;
 237                         }
 238                 }
 239                 return $file;
 240         }
 241
 242         /**
 243          * Find all instances of files with this key
 244          *
 245          * @param $hash String base 36 SHA-1 hash
 246          * @return Array of File objects
 247          */
 248         function findBySha1( $hash ) {
 249                 if ( !$this->reposInitialised ) {
 250                         $this->initialiseRepos();
 251                 }
 252
 253                 $result = $this->localRepo->findBySha1( $hash );
 254                 foreach ( $this->foreignRepos as $repo ) {
 255                         $result = array_merge( $result, $repo->findBySha1( $hash ) );
 256                 }
 257                 return $result;
 258         }
 259
 260         /**
 261          * Get the repo instance with a given key.
 262          * @return bool|LocalRepo
 263          */
 264         function getRepo( $index ) {
 265                 if ( !$this->reposInitialised ) {
 266                         $this->initialiseRepos();
 267                 }
 268                 if ( $index === 'local' ) {
 269                         return $this->localRepo;
 270                 } elseif ( isset( $this->foreignRepos[$index] ) ) {
 271                         return $this->foreignRepos[$index];
 272                 } else {
 273                         return false;
 274                 }
 275         }
 276         /**
 277          * Get the repo instance by its name
 278          * @return bool
 279          */
 280         function getRepoByName( $name ) {
 281                 if ( !$this->reposInitialised ) {
 282                         $this->initialiseRepos();
 283                 }
 284                 foreach ( $this->foreignRepos as $repo ) {
 285                         if ( $repo->name == $name)
 286                                 return $repo;
 287                 }
 288                 return false;
 289         }
 290
 291         /**
 292          * Get the local repository, i.e. the one corresponding to the local image
 293          * table. Files are typically uploaded to the local repository.
 294          *
 295          * @return LocalRepo
 296          */
 297         function getLocalRepo() {
 298                 return $this->getRepo( 'local' );
 299         }
 300
 301         /**
 302          * Call a function for each foreign repo, with the repo object as the
 303          * first parameter.
 304          *
 305          * @param $callback Callback: the function to call
 306          * @param $params Array: optional additional parameters to pass to the function
 307          * @return bool
 308          */
 309         function forEachForeignRepo( $callback, $params = array() ) {
 310                 foreach( $this->foreignRepos as $repo ) {
 311                         $args = array_merge( array( $repo ), $params );
 312                         if( call_user_func_array( $callback, $args ) ) {
 313                                 return true;
 314                         }
 315                 }
 316                 return false;
 317         }
 318
 319         /**
 320          * Does the installation have any foreign repos set up?
 321          * @return Boolean
 322          */
 323         function hasForeignRepos() {
 324                 return (bool)$this->foreignRepos;
 325         }
 326
 327         /**
 328          * Initialise the $repos array
 329          */
 330         function initialiseRepos() {
 331                 if ( $this->reposInitialised ) {
 332                         return;
 333                 }
 334                 $this->reposInitialised = true;
 335
 336                 $this->localRepo = $this->newRepo( $this->localInfo );
 337                 $this->foreignRepos = array();
 338                 foreach ( $this->foreignInfo as $key => $info ) {
 339                         $this->foreignRepos[$key] = $this->newRepo( $info );
 340                 }
 341         }
 342
 343         /**
 344          * Create a repo class based on an info structure
 345          */
 346         protected function newRepo( $info ) {
 347                 $class = $info['class'];
 348                 return new $class( $info );
 349         }
 350
 351         /**
 352          * Split a virtual URL into repo, zone and rel parts
 353          * @param $url string
 354          * @return array containing repo, zone and rel
 355          */
 356         function splitVirtualUrl( $url ) {
 357                 if ( substr( $url, 0, 9 ) != 'mwrepo://' ) {
 358                         throw new MWException( __METHOD__.': unknown protocol' );
 359                 }
 360
 361                 $bits = explode( '/', substr( $url, 9 ), 3 );
 362                 if ( count( $bits ) != 3 ) {
 363                         throw new MWException( __METHOD__.": invalid mwrepo URL: $url" );
 364                 }
 365                 return $bits;
 366         }
 367
 368         function getFileProps( $fileName ) {
 369                 if ( FileRepo::isVirtualUrl( $fileName ) ) {
 370                         list( $repoName, /* $zone */, /* $rel */ ) = $this->splitVirtualUrl( $fileName );
 371                         if ( $repoName === '' ) {
 372                                 $repoName = 'local';
 373                         }
 374                         $repo = $this->getRepo( $repoName );
 375                         return $repo->getFileProps( $fileName );
 376                 } else {
 377                         return FSFile::getPropsFromPath( $fileName );
 378                 }
 379         }
 380
 381         /**
 382          * Move a cache entry to the top (such as when accessed)
 383          */
 384         protected function pingCache( $key ) {
 385                 if ( isset( $this->cache[$key] ) ) {
 386                         $tmp = $this->cache[$key];
 387                         unset( $this->cache[$key] );
 388                         $this->cache[$key] = $tmp;
 389                 }
 390         }
 391
 392         /**
 393          * Limit cache memory
 394          */
 395         protected function trimCache() {
 396                 while ( count( $this->cache ) >= self::MAX_CACHE_SIZE ) {
 397                         reset( $this->cache );
 398                         $key = key( $this->cache );
 399                         wfDebug( __METHOD__.": evicting $key\n" );
 400                         unset( $this->cache[$key] );
 401                 }
 402         }
 403
 404         /**
 405          * Clear RepoGroup process cache used for finding a file
 406          * @param $title Title|null Title of the file or null to clear all files
 407          */
 408         public function clearCache( Title $title = null ) {
 409                 if ( $title == null ) {
 410                         $this->cache = array();
 411                 } else {
 412                         $dbKey = $title->getDBkey();
 413                         if ( isset( $this->cache[$dbKey] ) ) {
 414                                 unset( $this->cache[$dbKey] );
 415                         }
 416                 }
 417         }
 418 }